Reinforcer pathology,probabilistic choice,and medication adherence in patients with multiple sclerosis

The reinforcer pathology model posits that core behavioral economic mechanisms, including delay discounting and behavioral economic demand, underlie adverse health decisions and related clinical disorders. Extensions beyond substance use disorder and obesity, however, are limited. Using a reinforcer pathology framework, this study evaluates medical adherence decisions in patients with multiple sclerosis. Participants completed behavioral economic measures, including delay discounting, probability discounting, and a medication purchase task. A medical decision-making task was also used to evaluate how sensitivity to mild side effect risk and efficacy contributed to the likelihood of taking a hypothetical disease-modifying therapy. Less steep delay discounting and more intense (greater) medication demand were independently associated with greater adherence to the medication decision-making procedure. More generally, the pattern of interrelations between the medication-specific and general behavioral economic metrics was consistent with and contributes to the reinforcer pathology model. Additional research is warranted to expand these models to different populations and health behaviors, including those of a positive health orientation (i.e., medication adherence).     

A zero-bounded model of operant demand

Contemporary approaches for evaluating the demand for reinforcers use either the Exponential or the Exponentiated model of operant demand, both derived from the framework of Hursh and Silberberg (2008). This report summarizes the strengths and complications of this framework and proposes a novel implementation. This novel implementation incorporates earlier strengths and resolves existing shortcomings that are due to the use of a logarithmic scale for consumption. The Inverse Hyperbolic Sine (IHS) transformation is reviewed and evaluated as a replacement for the logarithmic scale in models of operant demand. Modeling consumption in the “log₁₀-like” IHS scale reflects relative changes in consumption (as with a log scale) and accommodates a true zero bound (i.e., zero consumption values). The presence of a zero bound obviates the need for a separate span parameter (i.e., k) and the span of the model may be more simply defined by maximum demand at zero price (i.e., Q₀). Further, this reformulated model serves to decouple the exponential rate constant (i.e., α) from variations in span, thus normalizing the rate constant to the span of consumption in IHS units and permitting comparisons when spans vary. This model, called the Zero-bounded Exponential (ZBE), is evaluated using simulated and real-world data. The direct reinstatement ZBE model showed strong correspondence with empirical indicators of demand and with a normalization of α (ZBEn) across empirical data that varied in reinforcing efficacy (dose, time to onset of peak effects). Future directions in demand curve analysis are discussed with recommendations for additional replication and exploration of scales beyond the logarithm when accommodating zero consumption data.     

The relationship between self-efficacy,readiness to change,and AUDIT risk levels in a sample of active duty emergency department patients

The purpose of this study was to test the relationship between self-efficacy, readiness to change, and Alcohol Use Disorders Identification Test (AUDIT) risk levels in a sample of active duty drinkers who were seeking care in a military emergency department. Civilian health educators screened participants for alcohol use with the AUDIT and collected sociodemographic, service, and drinking-related cognitions data from active duty patients admitted to an emergency department. A total of 787 active duty military personnel participated in the study. Almost half (48%) drank at least once a week and 32% reported consuming five or more alcoholic drinks during a typical drinking episode. One in five participants reported heavy episodic drinking weekly to almost daily. Results of a multinomial logistic regression model showed that active duty service members with a self-reported diagnosis of posttraumatic stress disorder since joining the military were more likely to be an at-risk or high/severe risk drinker relative to a low risk drinker. Higher controlled drinking self-efficacy was associated with a decrease in the odds of being either an at-risk or high/severe risk drinker. Increased readiness to reduce drinking was associated with an increase in the odds of being either an at risk or high/severe risk drinker. The results of this research suggest self-efficacy to control one’s heavy drinking as well as readiness to change may be important factors to consider when designing alcohol education programs within the military.     

Over‐selective Responding in a Diagnostic Judgment Task

Medical diagnoses are often made on the basis of the presence of multiple symptoms. However, little is known about how the presence of multiple simultaneous symptoms may influence a bias in determining which symptoms are identified, in part due to a lack of an experimental analogue of this process. The current article presents a laboratory analogue of this process and explores whether over‐selectivity influences the ability to identify symptoms indicative of particular illnesses. In two experiments, participants completed a diagnosis task that required them to rate the degree to which symptoms predicted illnesses, with predictor symptoms being presented either singly or in compound. In both experiments, over‐selectivity was observed; one symptom of the compound received lower ratings, compared to the other element of the compound and the single predictor, while the other component received comparable ratings with the element. These findings are discussed in relation to associative accounts of over‐selectivity and as a procedure to study biases in medical decision making.Copyright © 2017 John Wiley & Sons, Ltd.     

A Qualitative Study of Factors Influencing Decision-Making after Prenatal Diagnosis of down Syndrome

Previous research has identified twenty-six factors that may affect pregnancy management decisions following prenatal diagnosis of DS; however, there is no consensus about the relative importance or effects of these factors. In order to better understand patient decision-making, we conducted expansive cognitive interviews with nine former patients who received a prenatal diagnosis of DS. Our results suggest that patients attached unique meanings to factors influencing decision-making regardless of the pregnancy outcome. Nineteen of the twenty-six factors previously studied and four novel factors (rationale for testing, information quality, pregnancy experience, and perception of parenting abilities and goals) were found to be important to decision-making. We argue that qualitative studies can help characterize the complexity of decision-making following prenatal diagnosis of DS.     

Confirmation of correlation between brain nerve conduction velocity and intelligence level in normal adults

In 1992, Reed and Jensen [Intelligence 16 (1992) 259–272] reported a positive correlation (.26; p=.002; .37 after correcting for restricted intelligence range) between a brain nerve conduction velocity (NCV) and intelligence level in 147 normal male students. In the first follow-up of their study, we report on a study using similar NCV methodologies, but testing both male and female students and using more extensive measures of cognitive abilities. One-hundred eighty-six males and 201 females, aged 18–25 years, were tested in three different NCV conditions and with nine cognitive tests, including Raven Progressive Matrices as used by Reed and Jensen. None of the 27 independent correlations in either the males or in the females are significant at Bonferroni-corrected probability levels, but 25 of 27 correlations in males and 20 of 27 correlations in females have positive signs. The exact binomial probabilities for these results are 5.6×10⁻⁶ and .002, respectively. We discuss possible reasons for the differences between the results of Reed and Jensen and our results. We also find that males have four percent faster NCVs than females with each of the three test conditions, probably due to their faster increase of white matter in the brain during adolescence.     

Latent inhibition and context change in psychometrically defined schizotypy

The disruption of latent inhibition within the schizophrenia spectrum has often been interpreted either as a result of increased attentional distractibility (attentional account) or as a result of deficient interference of past associations (associative account). The aim of the present investigation was to test competing predictions, as derived from the above theoretical accounts. In a visual search paradigm of latent inhibition, accuracy was examined as a function of prior experience with the target, and psychometrically defined schizotypy. In Experiment 1 (N=60), no context change was introduced. In accord with past evidence, latent inhibition was found to be intact in low-, but disrupted in high-schizotypy scorers, a result predicted both by attentional and associative accounts. In Experiment 2 (N=60), a context change was introduced. As predicted by past evidence, latent inhibition was disrupted in low-schizotypy scorers. However, latent inhibition was found to be intact in high-schizotypy scorers, a finding accommodated by attentional, but not associative accounts. Theoretical implications and alternative interpretations are also considered.